r PREFACE TO THE FIRST EDITION organic substances on a broader and therefore more rational basis. 1 The present occasion seems opportune to direct attention to the fact that one of the most familiar, most readily procurable and most cheaply produced of all organic materials is placed beyond the reach of many students by the heavy duty levied upon it. May I, in the name of teachers of organic chemistry, .appeal to the Board of Inland Revenue, on behalf of scientific and technical education, to .provide institutions for higher education in science with a limited quantity of pure alcohol free of duty, thereby placing schools of chemistry in this country in the same position as those on the Continent ? In conclusion I desire to thank Dr. J. McCrae, who has written the section on Ethyl Tartrate and the use of the Polari- meter, Dr. T. S. Patterson, who has been kind enough to look Ľover the proofs, and Mr. H. D. Dakin, who has given me sub- stantial assistance in the practical work of revision. J. B. COHEN. THE YORKSHIRE COLLEGE, October, 1900.